1. Field of the Invention
The present invention relates to pay information providing systems, and more specifically, relates to a system for providing pay information such as picture data, audio data, computer data, etc., from a transmitting station (a broadcast satellite, a communication satellite, a center station of CATV, a ground broadcast station, etc.) managed by an information provider to a receiving station which makes a receive contract with the information provider.
2. Description of the Background Art
As an example of accounting methods in the conventional pay information providing system, an accounting method in a pay broadcasting system using a broadcast satellite will be described. FIG. 16 is a block diagram showing the whole structure of the pay broadcasting system using a broadcast satellite. In FIG. 16, in the above pay broadcasting system, a transmitting device 100 transmitting pay information such as digitized picture and audio and a receiving device 107 receiving the pay information are connected through a transmission path 106. The receiving device 107 can receive the transmitted pay information and the like with an IC card 108 being set thereto.
The transmitting device 100 comprises a scramble key generating portion 101 generating a scramble key, a scrambler 102 scrambling pay information, a related information encrypting portion 103 encrypting related information (information concerning a contract with a user) and the scramble key, a charge managing portion 104 managing a charge to be made to the user, and a multiplex/transmitting portion 105 multiplexing and transmitting the scrambled pay information and the encrypted related information and the like.
The receiving device 107 comprises a receiving/demultiplex portion 109 receiving and demultiplexing the multiplexed pay information and the related information and the like, a descrambler 110 descrambling the pay information using the scramble key, and a picture/audio decoder 111 decoding the descrambled pay information to output picture data, audio data and like. The IC card 108 comprises a related information decrypting portion 112 decrypting the encrypted related information and the encrypted scramble key and a qualification judging portion 113 judging whether the receiving device 107 has qualification for receiving the pay information or not by examining the decrypted related information and giving the scramble key attached to the related information to the descrambler 110 only when the receiving device 107 has the qualification.
In the pay broadcasting system having the above structure, an information provider makes a charge for providing and using the pay information in such a manner as described below. First, the user purchases and installs equipment for receiving the pay information (the receiving device 107 and the IC card 108). At the same time, the user makes a contract in regard to providing the pay information with the information provider using communication means such as a telephone. Registered thereby in the transmitting device 100 managed by the information provider is the above mentioned contract information. This contact information is also registered in the qualification judging portion 113.
After finishing the above mentioned registration, when the transmitting device 100 receives a request from the user, the scramble key generating portion 101 generates a scramble key, sets the generated scramble key to the scrambler 102, and outputs the key to the related information encrypting portion 103. The related information encrypting portion 103 encrypts related information including the contract information of the user who sends the request and the like and the scramble key and outputs the result to the multiplex/transmitting portion 105. On the other hand, the scrambler 102 scrambles the requested pay information by using the set scramble key and then outputs the results to the multiplex/transmitting portion 105. The multiplex/transmitting portion 105 multiplexes the encrypted related information and scramble key and the scrambled pay information and transmits the result through the transmission path 106 to the receiving/demultiplex portion 109 in the receiving device 107. At this time, inputted in the charge managing portion 104 is the related information including the contract information of the user who sends the request and the like. In response, the charge managing portion 104 calculates a charge for using the pay information to the user and stores information about the charge for use.
The receiving/demultiplex portion 109 demultiplexes the information received through the transmission path 106 into the encrypted related information and scramble key and the scrambled pay information and outputs the former to the related information decrypting portion 112 and the latter to the descrambler 110, respectively. The related information decrypting portion 112 decrypts the encrypted related information and scramble key, and then outputs these to the qualification judging portion 113. The qualification judging portion 113 judges whether the user who holds the receiving device 107 makes the contract with the information provider or not based on the contract information included in the related information and the contract information registered therein, and outputs the inputted scramble key to the descrambler 110 only when judging positively. The descrambler 110 descrambles the inputted pay information and outputs the result to the picture/audio decoder 111. The pay information decoded by the picture/audio decoder 111 is outputted as picture data or audio data. The user thereby acquires the pay information from the information provider. The information provider managing the transmitting device 100 charges the user for use of the pay information at the time defined by the contract (at the end of the month, for example), based on information about charges stored in the charge managing portion 104.
By the way, recent technological innovation has upgraded infrastructure as to broadcasting and information communications, and various information (picture information, audio information, character information, figure information, etc.) can be obtained even at home from information providers. These kinds of information are transmitted to homes, for example, from a ground broadcast station, satellite broadcasting, or a communication satellite by radio, or, transmitted from a center station of CATV (Cable Television) through wire such as optical fiber cables.
Further, conventionally, it is a general style at home that only one television is installed in a living room or the like and all family members watch a television program. However, in recent years, televisions have been installed in a plurality of rooms and each individual watches his/her favorite television program. This personal-oriented trend will be more apparent in the future.
As described above, in order to allow acquisition of various information at each home and adapt the situation where the personal-oriented trend progresses, it can be suggested to construct two pay information providing systems as will described below. That is, in a first pay information providing system, the above mentioned receiving equipment (the receiving device 107 and the IC card 108) is installed in each room as required at home. On the other hand, in a second pay information providing system, one piece of the receiving equipment is installed per household and the pay information is branched to be inputted to a television in each room. Each individual at home watches the pay information using the individual television.
However, when the above first pay information providing system is adapted, it is required to install the receiving equipment (the receiving device 107 and the IC card 108) in each room as required at home, thereby increasing initial expenses for the equipment at the user's side. Further, in the first pay information providing system, it is required to make a plurality of contracts with the information provider, in response to the number of installed receiving equipment. Therefore, when the same television program is watched by two televisions in one home, the household has to pay a double charge for use for the same television program. However, the user seems to feel uncomfortable to pay the double charge for the same television program.
On the other hand, when the above second pay information providing system is adapted, it is a disadvantage that billing cannot be made in response to the number of televisions. More specifically, for example, assume that one receiving equipment is installed in one home and ten televisions are connected to the receiving equipment. In this case, either when a television program is watched by one television or when a television program is watched by ten televisions, the charges which are paid to the information provider are the same. However, the information provider seems to want to bill the household for charges according to the number of the installed televisions. The user who holds only one television seems to think unreasonable to be billed for the same charges as the user who holds ten televisions.